Summary

Background

Selenium IDE can be extensively customised via Core extensions (written in Javascript). This way you add new Selenese commands and related functionality. Many extensions are worth reusing (by yourself, within your team or publicly). But then they often need to be configured, e.g. in regard of

users or credentials

location of XML files (which an extension can pass to loadXmlVars and forXml from SelBlocks Global)

no need for sophistication, since it won’t be used frequently (as compared to other GUI parts of Selenium IDE)

done once for benefit of many

easier to use, share and manage than

editing Javascript files (possible typos..), or

using Firefox’s special URL about:config, which would

hard-code preference names

allow only one configuration per Firefox profile. That is counter productive if you need to switch between configurations, since the profile contains the installed extensions, history etc. Copying the profile folders can lead to a mess.